Road-side verges : habitat and corridor for carabid beetles of poor sandy and open areas

Investigates the question whether or not heathy strips, like poor sandy and open roadside verges, can direct dispersal movements of stenotopic carabid beetles from one heathland fragment towards another, and under what conditions. By placing pitfall traps at ten heathy roadside verges in the north-eastern part of the Netherlands it was established that beetles of poor sandy and open habitats do not avoid road verges. A relation was found for the species occurring at the verge with both distance to a heathland fragment and width of the heathy strip at the verge. It was found that beetles stay in their corridor by the avoidance of the bordering areas. Distances walked per day in different kinds of habitat and chances of entering different kinds of habitat were accumulated in a simulation program. Recommendation for the creation and management of dispersal corridors could be formulated.